Organ simulators to simulate dynamics of organs have been developed, and it is expected that such organ simulators are used for diagnosis, determination of a treatment policy, prediction of postoperative condition and the like. It is favorable that an organ shape used for simulation is analogous to an actual organ shape to the extent possible, in order to make the reliability of the simulator higher.
An organ shape differs from patient to patient, and using a uniform shape is not allowed. Therefore, an organ shape used in simulation is generated for each patient. However, because organs exist in a human body and they are invisible and directly unmeasurable, they are generated based on patient's medical images such as CT (Computed Tomography) images or MRI (Magnetic Resonance Imaging) images. A certain document discloses a technique to generate an organ shape of a patient by transforming a template representing a standard shape of an organ based on landmarks deployed on patient's medical images.
However, a technique to generate an organ shape with attention to an annular structure in the organ is unknown. For example, a heart has a pulmonary valve, an aortic valve, a mitral valve and a tricuspid valve. And an edge of each valve is called a valve annulus. Because the valve annulus plays an important role when a heart serves as a pump, generating a high-accuracy shape in the vicinity of the valve annulus makes the reliability of the simulation higher.    Patent Document 1: Japanese Laid-open Patent Publication No. 2013-015945    Non-Patent Document 1: “A Multi-scale Approach to 3D Scattered Data Interpolation with Compactly Supported Basis Functions”, Yutaka Ohtake, Alexander Belyaev, and Hans-Peter Seidel, Shape Modeling International 2003, Seoul, Korea, May 2003, pp 153-161
In other words, there is no technique to generate a high-accuracy shape of an object including an annular structure.